Histiocytosis

Abnormal appearance of histiocytes in the blood, (Histiocytes are produced by the bone marrow and are normally immobile until stimulated by inflammation, They are a type of antigen presenting cell, )

• cutaneous benign proliferation of nodules in or under the skin
• malignant a rapidly invasive proliferation of neoplastic (new growth) histiocytes, No known treatment, always fatal,
• systemic proliferation of histiocytes invading the skin and lymph nodes, Can go into remission for years, or progress to the malignant form, Can be treated, but not cured,